Concept

Expressing Multiple Unknowns in Terms of a Single Variable

When a word problem asks for two or more unknown numbers, it may seem natural to assign each unknown its own separate variable. However, at the introductory algebra level, equations are solved for a single variable only. The strategy for handling multiple unknowns is to express every unknown quantity in terms of one chosen variable by using the relationships stated in the problem. This requires careful reading to identify how the numbers relate to one another. For example, if one number is described as "five more than" another, the first number can be represented as nn and the second as n+5n + 5. By writing all quantities through a single variable, the resulting equation contains only one unknown and can be solved with standard algebraic techniques.

0

1

Updated 2026-04-22

Contributors are:

Who are from:

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.3 Math Models - Elementary Algebra @ OpenStax

Algebra

Math

Ch.5 Systems of Linear Equations - Elementary Algebra @ OpenStax

Prealgebra

Intermediate Algebra @ OpenStax

Ch.2 Solving Linear Equations - Intermediate Algebra @ OpenStax

Related
Learn After